Air-supply for boiler-furnaces



(No Model'.)

1. v. SCHOLPIELD, Jr. AIR SUPPLY FOR BOILER FURNACES.

No. 481,831. Patented Aug. 30, 1892;

UNITED STATES PATENT Fries.

IRA V. SCHOLFIELD, JR, OF SAN FRANCISCO, CALIFORNIA.

AIR-SUPPLY FOR BOILER-FURNACES.

SPECIFICATION forming part of Letters Patent No. 481,831, dated August 30, 1892.

Application filed July 28, 1891.

To all whom, it may concern:

Be it known that I, IRA V. SOHOLFIELD, J r., a citizen of the United States, residing in the city and county of San Francisco, State of California, have invented an Improvement in Air-Supplies for Boiler-Furnaces; andl hereby declare the following to be a full, clear, and exact description of the same.

My invention relates to an improved device and means for supplying air to boiler-furnaces.

It consists of a chamber surrounding the upper part of the furnace, with doors or openings through which air is admitted into the chamber, where it is heated from the furnace and is directed around the sides of the firedoor into the ash-pit below the grate-bars, from which it passes into the fuel-space.

It also consists in certain details of construction, which will be more fully explained by reference to the accompanying drawings, in which- 7 Figure 1 is a vertical transverse section on the line a: a: of Fig. 2, looking to the front. Fig. 2 is a vertical longitudinal section through the center of the boiler. Fig. 3 is a longitudinal horizontal section on the line yr of Fig. 1. Fig. at is a vertical transverse section on the line 2 z of Fig. 3, looking toward the rear.

In the present case I have shown my invention as applied to a boiler of that class in which the grate and fire-box are situated in a large flue, which extends through the lower part of the-boiler to a combustion-chamber in the rear, from which the products of combustion are returned to the front through small tubes above and around the large flue, these tubes connecting with the uptake and smokestack at the front of the boiler.

A is the boiler, and B is a large flue extending through the lower part.

(J are the return-tubes, through which the products of combustion reach the smoke stack.

Within the large tube and near the front is formed a casing D,'having a vertical plate or diaphragm a surrounding the upper portion and sides of the front portion of the flue, and having, also, the vertical side plates or diaphragmsb and upper and lower horizontal plates 0 and c, which form the walls of the opening through which the fuel is introduced Serial No. 400,991. (No model.)

to the sides of the flue B and provided with openings J, while the plates b and lower side portions of the plate or diaphragm a are provided with openings L for supplying heated air to the furnace above the grate-bars.

F are doors or gates opening through the front of the boiler above the fire-door G, so that air may enterinto this casing or chamber through these doors. The doors are made adj ustable in any suitable or. desired manner to control the admission of air into the casing.

H are the grate-bars within the fire-box, upon which the fuel is burned, and I is the ash-pit beneath these grate-bars. The front of this ash-pit remains closed, and air being admitted through the doors F into the upper part of the casing passes down around each side of the front portion of the fire-box and is delivered through openings J into the ashpit beneath the grate. The heat radiating from the fire into the casing raises the temperature of this air to a high degree, so that when it is delivered to the fuel it does not reduce the temperature of the latter, and the improvement in the combustion thus caused is very great. 7

M is the bridge-wall at the rear of the furnace, over which the products of combustion pass to the rear of the boiler.

K K are pipes extending through the front of the boiler beneath the grate and opening through the bridge-wall into the space behind. These pipes are of any suitable or desired size and have controlling valves or gates K, through which a supply of air passes. The air passing through these pipes is also heated from the fire on the grate and is delivered to the space behind the bridge-wall, where it meets the unconsumed products of combustion and supplies a further quantity of air fora more-complete combustion ofthese products.

L L are small holes opening from the chamber or casing D into the furnace above the grate-bars, and these holes supply heated air for more perfect combustion at this point.

The whole device is simple and easily applied to any boiler and is extremely efficient.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

to the grate-bars, said plate 0 being extended ing of the combination of a main circular flue I phragm at, having opening L for delivering [0 B, a casing D, consisting of a vertical plate or heated air to the furnace, and the doors F and diaphragm a, surrounding the upper portion G, substantially as herein described. and sides of the front portion of the fine, and In witness whereof I have hereunto set my 5 the plates or diaphragms b, c, and 0', formhand.

ing the walls of the opening through which IRA V. SCIIOLFIELD, JR. the fuel is introduced, said plate 0' having \Vitnesses: openings J, and the plates or diaphragms b S. H. NOURSE,

and lower side portion of the plate or dia- J. A. BAYLESS. 

